Ink-jet printhead nozzles often become plugged with dried ink particulate, unless they are kept in a humid environment. Commonly, an elastomer cap is placed over the nozzle end of a printhead to ensure a sufficiently humid environment to avoid such undesirable dried ink formation. Such a cap must form a leak-free seal between the printhead's nozzle and the ambient environment. Conventionally, this has been done in one of two ways: by forcing the elastomer cap into the printhead with enough force to deform the cap around its sealing lip, or by providing a spring-loaded gimbaling mechanism behind the cap to allow the cap's lip to "float" with the printhead. The former typically requires large forces to produce sufficient deformation to ensure a reliable seal, due to manufacturing tolerances. The latter typically requires less force, but adds a significant number of parts, thus increasing the cost and complexity of the cap mechanism. Neither is well-suited to multiple printhead ink-jet printer systems.
Certain improvements in ink-jet printhead capping mechanisms, more particularly to non-clogging configurations of a cap and a service station wherein the former sealingly engages an ink-jet printhead, have been proposed. Such are described in U.S. Pat. No. 5,027,134 entitled "Non-Clogging Cap and Service Station for Ink-jet Printers", which issued Jun. 25, 1991 and which is commonly owned herewith. The disclosure of that patent is incorporated herein by this reference.